Playback device calibration

ABSTRACT

Systems and methods for calibrating a playback device include (i) outputting first audio content; (ii) capturing audio data representing reflections of the first audio content within a room in which the playback device is located; (iii) based on the captured audio data, determining an acoustic response of the room; (iv) connecting to a database comprising a plurality of sets of stored audio calibration settings, each set associated with a respective stored acoustic room response of a plurality of stored acoustic room responses; (v) querying the database for a stored acoustic room response that corresponds to the determined acoustic response of the room in which the playback device is located; and (vi) applying to the playback device a particular set of stored audio calibration settings associated with the stored acoustic room response that corresponds to the determined acoustic response of the room in which the playback device is located.

FIELD OF THE DISCLOSURE

The present disclosure is related to consumer goods and, moreparticularly, to methods, systems, products, features, services, andother elements directed to media playback or some aspect thereof.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2002, when SONOS, Inc. began developmentof a new type of playback system. Sonos then filed one of its firstpatent applications in 2003, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering itsfirst media playback systems for sale in 2005. The Sonos Wireless HomeSound System enables people to experience music from many sources viaone or more networked playback devices. Through a software controlapplication installed on a controller (e.g., smartphone, tablet,computer, voice input device), one can play what she wants in any roomhaving a networked playback device. Media content (e.g., songs,podcasts, video sound) can be streamed to playback devices such thateach room with a playback device can play back corresponding differentmedia content. In addition, rooms can be grouped together forsynchronous playback of the same media content, and/or the same mediacontent can be heard in all rooms synchronously.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings, as listed below. A personskilled in the relevant art will understand that the features shown inthe drawings are for purposes of illustrations, and variations,including different and/or additional features and arrangements thereof,are possible.

FIG. 1A is a partial cutaway view of an environment having a mediaplayback system configured in accordance with aspects of the disclosedtechnology.

FIG. 1B is a schematic diagram of the media playback system of FIG. 1Aand one or more networks.

FIG. 1C is a block diagram of a playback device.

FIG. 1D is a block diagram of a playback device.

FIG. 1E is a block diagram of a network microphone device.

FIG. 1F is a block diagram of a network microphone device.

FIG. 1G is a block diagram of a playback device.

FIG. 1H is a partially schematic diagram of a control device.

FIG. 2A is a diagram of a playback environment within which a playbackdevice may be calibrated.

FIG. 2B is a block diagram of a database for storing room response dataand corresponding playback device calibration settings.

FIG. 2C is a diagram of a playback environment within which a playbackdevice may be calibrated.

FIG. 3A is a flowchart of a method for populating a database with roomresponse data and corresponding playback device calibration settings.

FIG. 3B is a flowchart of a method for calibrating a playback deviceusing a database populated with room response data and correspondingplayback device calibration settings.

The drawings are for the purpose of illustrating example embodiments,but those of ordinary skill in the art will understand that thetechnology disclosed herein is not limited to the arrangements and/orinstrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Any environment has certain acoustic characteristics (“acoustics”) thatdefine how sound travels within that environment. For instance, with aroom, the size and shape of the room, as well as objects inside thatroom, may define the acoustics for that room. For example, angles ofwalls with respect to a ceiling affect how sound reflects off the walland the ceiling. As another example, furniture positioning in the roomaffects how the sound travels in the room. Various types of surfaceswithin the room may also affect the acoustics of that room; hardsurfaces in the room may reflect sound, whereas soft surfaces may absorbsound. Accordingly, calibrating a playback device within a room so thatthe audio output by the playback device accounts for (e.g., offsets) theacoustics of that room may improve a listening experience in the room.

U.S. Pat. No. 9,706,323 entitled, “Playback Device Calibration,” andU.S. Pat. No. 9,763,018 entitled, “Calibration of Audio PlaybackDevices,” which are hereby incorporated by reference in their entirety,provide examples of calibrating playback devices to account for theacoustics of a room.

An example calibration process for a media playback system involves aplayback device outputting audio content while in a given environment(e.g., a room). The audio content may have predefined spectral content,such as a pink noise, a sweep, or a combination of content. Then, one ormore microphone devices detect the outputted audio content at one ormore different spatial positions in the room to facilitate determiningan acoustic response of the room (also referred to herein as a “roomresponse”).

For example, a mobile device with a microphone, such as a smartphone ortablet (referred to herein as a network device) may be moved to thevarious locations in the room to detect the audio content. Theselocations may correspond to those locations where one or more listenersmay experience audio playback during regular use (i.e., listening) ofthe playback device. In this regard, the calibration process involves auser physically moving the network device to various locations in theroom to detect the audio content at one or more spatial positions in theroom. Given that this acoustic response involves moving the microphoneto multiple locations throughout the room, this acoustic response mayalso be referred to as a “multi-location acoustic response.”

Based on a multi-location acoustic response, the media playback systemmay identify an audio processing algorithm. For instance, a networkdevice may identify an audio processing algorithm, and transmit to theplayback device, data indicating the identified audio processingalgorithm. In some examples, the network device identifies an audioprocessing algorithm that, when applied to the playback device, resultsin audio content output by the playback device having a target audiocharacteristic, such as a target frequency response at one or morelocations in the room. The network device can identify the audioprocessing algorithm in various ways. In one case, the network devicedetermines the audio processing algorithm based on the data indicatingthe detected audio content. In another case, the network device sends,to a computing device such as a server, data indicating the audiocontent detected at the various locations in the room, and receives,from the computing device, the audio processing algorithm after theserver (or another computing device connected to the server) hasdetermined the audio processing algorithm.

In some circumstances, performing a calibration process such as the onedescribed above is not feasible or practical. For example, a listenermight not have access to a network device that is capable of orconfigured for performing such a calibration process. As anotherexample, a listener may choose not to calibrate the playback devicebecause of they find the process of moving the microphone around theroom inconvenient or otherwise burdensome.

Disclosed herein are systems and methods to help address these or otherissues. In particular, a playback device in an environment is configuredto calibrate itself with respect to the environment without using anetwork device to detect audio content at various locations in the room.To do so, the playback device leverages a database of calibrationsettings (e.g., audio processing algorithms) that have been generatedfor other playback devices using a calibration process, such as theprocess described above. Given a sufficiently large database ofcalibration settings, the database becomes statistically capable ofproviding a set of calibration settings that are appropriate forcalibrating the playback device to account for the acoustic response ofits environment.

In practice, such a database is populated with calibration settings byvarious playback devices performing a calibration process similar to theprocess described above. Namely, the database is populated by performinga calibration process for each playback device of a number of playbackdevices that involves each playback device outputting audio content in aroom, moving a network device to various locations in the room todetermine a multi-location acoustic response of the room, anddetermining the calibration settings based on the room's multi-locationacoustic response. This process is repeated by a large number of usersin a larger number of different rooms, thereby providing a statisticallysufficient volume of different room responses and correspondingcalibration settings.

Further, a playback device may include its own microphone, which theplayback device uses to determine an acoustic response of the roomdifferent from the multi-location acoustic response of the room. Whilethe playback device outputs audio content for determining themulti-location acoustic response of the room as described above, theplayback device concurrently uses its own microphone to detectreflections of the audio content within the room and determines adifferent acoustic response of the room based on the detectedreflections (as compared with the acoustic response determined based onthe reflections detected by a network device). This acoustic responsedetermined by the playback device may be referred to as a “localizedacoustic response,” as the acoustic response is determined based oncaptured audio localized at the playback device, rather than at multiplelocations throughout the room via the microphone of the network device.Data representing the localized acoustic response and data representingthe calibration settings are then stored in the database and associatedwith one another. As a result, the database is populated with a numberof records, each record corresponding to a respective playback device,and each record including data representing the respective playbackdevice's localized acoustic response and the respective playbackdevice's calibration settings for the localized acoustic response.

Once the database is populated, media playback systems can access thedatabase to determine suitable calibration settings without requiringthe use of a network device to first determine a multi-location acousticresponse for a room in which the playback device(s) of that system arelocated. For instance, the playback device determines a localizedacoustic response for the room by outputting audio content in the roomand using a microphone of the playback device to detect reflections ofthe audio content within the room. The playback device then queries thedatabase to identify a stored localized acoustic response that issubstantially similar to, or that is most similar to, the localizedacoustic response determined by the playback device. The playback devicethen applies to itself the identified calibration settings that areassociated in the database with the identified localized acousticresponse.

The above playback device calibration process may be initiated atvarious times and/or in various ways. In some examples, calibration ofthe playback device is initiated when the playback device is being setup for the first time, when the playback device plays music for thefirst time, or if the playback device has been moved to a new location.For instance, if the playback device is moved to a new location,calibration of the playback device may be initiated based on a detectionof the movement or based on a user input indicating that the playbackdevice has moved to a new location. In some examples, calibration of theplayback device is initiated on demand via a controller device. Further,in some examples, calibration of the playback device is initiatedperiodically, or after a threshold amount of time has elapsed after aprevious calibration, in order to account for changes to the environmentof the playback device and/or changes to the database of calibrationsettings.

Accordingly, in some implementations, for example, a playback deviceoutputs first audio content via one or more speakers of the playbackdevice, and the playback device captures audio data representingreflections of the first audio content within a room in which theplayback device is located via one or more microphones of the playbackdevice. Based on the captured audio data, the playback device determinesan acoustic response of the room in which the playback device islocated. Further, the playback device establishes a connection with adatabase populated with a plurality of sets of stored audio calibrationsettings, each set associated with a respective stored acoustic roomresponse of a plurality of stored acoustic room responses. The pluralityof sets of stored audio calibration settings are determined based onmultiple media playback systems each performing a respective audiocalibration process, which includes (i) outputting, via a respectiveplayback device within a respective room that is different from the roomin which the playback device is located, respective audio content, (ii)while the respective playback device outputs the respective audiocontent, capturing, via a microphone of a respective network device incommunication with the respective playback device, first respectiveaudio data representing reflections of the respective audio content inthe respective room while the respective network device is moving from afirst physical location to a second physical location within therespective room, and (iii) based on the first respective audio data,determining a set of audio calibration settings for the respectiveplayback device. Additionally, the plurality of stored acoustic roomresponses are determined based on the multiple media playback systemseach performing a respective acoustic room response determinationprocess, which includes (i) while the respective playback device outputsthe respective audio content, capturing, via a microphone disposed in ahousing of the respective playback device, second respective audio datarepresenting reflections of the respective audio content in therespective room, and (ii) based on the second respective audio data,determining an acoustic response of the respective room. Once theplayback device has established a connection with the database, theplayback device queries the database for a stored acoustic room responsethat corresponds to the determined acoustic response of the room inwhich the playback device is located. Responsive to the query, theplayback device applies to itself a particular set of stored audiocalibration settings associated with the stored acoustic room responsethat corresponds to the determined acoustic response of the room inwhich the playback device is located. The playback device then outputs,via one or more of its speakers, second audio content using theparticular set of audio calibration settings associated with the storedacoustic room response that corresponds to the determined acousticresponse of the room in which the playback device is located.

While some examples described herein may refer to functions performed bygiven actors such as “users,” “listeners,” and/or other entities, itshould be understood that this is for purposes of explanation only. Theclaims should not be interpreted to require action by any such exampleactor unless explicitly required by the language of the claimsthemselves.

In the Figures, identical reference numbers identify generally similar,and/or identical, elements. To facilitate the discussion of anyparticular element, the most significant digit or digits of a referencenumber refers to the Figure in which that element is first introduced.For example, element 110 a is first introduced and discussed withreference to FIG. 1A. Many of the details, dimensions, angles and otherfeatures shown in the Figures are merely illustrative of particularembodiments of the disclosed technology. Accordingly, other embodimentscan have other details, dimensions, angles and features withoutdeparting from the spirit or scope of the disclosure. In addition, thoseof ordinary skill in the art will appreciate that further embodiments ofthe various disclosed technologies can be practiced without several ofthe details described below.

II. Suitable Operating Environment

FIG. 1A is a partial cutaway view of a media playback system 100distributed in an environment 101 (e.g., a house). The media playbacksystem 100 comprises one or more playback devices 110 (identifiedindividually as playback devices 110 a-n), one or more networkmicrophone devices (“NMDs”) 120 (identified individually as NMDs 120a-c), and one or more control devices 130 (identified individually ascontrol devices 130 a and 130 b).

As used herein the term “playback device” can generally refer to anetwork device configured to receive, process, and output data of amedia playback system. For example, a playback device can be a networkdevice that receives and processes audio content. In some embodiments, aplayback device includes one or more transducers or speakers powered byone or more amplifiers. In other embodiments, however, a playback deviceincludes one of (or neither of) the speaker and the amplifier. Forinstance, a playback device can comprise one or more amplifiersconfigured to drive one or more speakers external to the playback devicevia a corresponding wire or cable.

Moreover, as used herein the term NMD (i.e., a “network microphonedevice”) can generally refer to a network device that is configured foraudio detection. In some embodiments, an NMD is a stand-alone deviceconfigured primarily for audio detection. In other embodiments, an NMDis incorporated into a playback device (or vice versa).

The term “control device” can generally refer to a network deviceconfigured to perform functions relevant to facilitating user access,control, and/or configuration of the media playback system 100.

Each of the playback devices 110 is configured to receive audio signalsor data from one or more media sources (e.g., one or more remoteservers, one or more local devices) and play back the received audiosignals or data as sound. The one or more NMDs 120 are configured toreceive spoken word commands, and the one or more control devices 130are configured to receive user input. In response to the received spokenword commands and/or user input, the media playback system 100 can playback audio via one or more of the playback devices 110. In certainembodiments, the playback devices 110 are configured to commenceplayback of media content in response to a trigger. For instance, one ormore of the playback devices 110 can be configured to play back amorning playlist upon detection of an associated trigger condition(e.g., presence of a user in a kitchen, detection of a coffee machineoperation). In some embodiments, for example, the media playback system100 is configured to play back audio from a first playback device (e.g.,the playback device 100 a) in synchrony with a second playback device(e.g., the playback device 100 b). Interactions between the playbackdevices 110, NMDs 120, and/or control devices 130 of the media playbacksystem 100 configured in accordance with the various embodiments of thedisclosure are described in greater detail below with respect to FIGS.1B-1H.

In the illustrated embodiment of FIG. 1A, the environment 101 comprisesa household having several rooms, spaces, and/or playback zones,including (clockwise from upper left) a master bathroom 101 a, a masterbedroom 101 b, a second bedroom 101 c, a family room or den 101 d, anoffice 101 e, a living room 101 f, a dining room 101 g, a kitchen 101 h,and an outdoor patio 101 i. While certain embodiments and examples aredescribed below in the context of a home environment, the technologiesdescribed herein may be implemented in other types of environments. Insome embodiments, for example, the media playback system 100 can beimplemented in one or more commercial settings (e.g., a restaurant,mall, airport, hotel, a retail or other store), one or more vehicles(e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane),multiple environments (e.g., a combination of home and vehicleenvironments), and/or another suitable environment where multi-zoneaudio may be desirable.

The media playback system 100 can comprise one or more playback zones,some of which may correspond to the rooms in the environment 101. Themedia playback system 100 can be established with one or more playbackzones, after which additional zones may be added, or removed to form,for example, the configuration shown in FIG. 1A. Each zone may be givena name according to a different room or space such as the office 101 e,master bathroom 101 a, master bedroom 101 b, the second bedroom 101 c,kitchen 101 h, dining room 101 g, living room 101 f, and/or the balcony101 i. In some aspects, a single playback zone may include multiplerooms or spaces. In certain aspects, a single room or space may includemultiple playback zones.

In the illustrated embodiment of FIG. 1A, the master bathroom 101 a, thesecond bedroom 101 c, the office 101 e, the living room 101 f, thedining room 101 g, the kitchen 101 h, and the outdoor patio 101 i eachinclude one playback device 110, and the master bedroom 101 b and theden 101 d include a plurality of playback devices 110. In the masterbedroom 101 b, the playback devices 110 l and 110 m may be configured,for example, to play back audio content in synchrony as individual onesof playback devices 110, as a bonded playback zone, as a consolidatedplayback device, and/or any combination thereof. Similarly, in the den101 d, the playback devices 110 h-j can be configured, for instance, toplay back audio content in synchrony as individual ones of playbackdevices 110, as one or more bonded playback devices, and/or as one ormore consolidated playback devices. Additional details regarding bondedand consolidated playback devices are described below with respect toFIGS. 1B and 1E.

In some aspects, one or more of the playback zones in the environment101 may each be playing different audio content. For instance, a usermay be grilling on the patio 101 i and listening to hip hop music beingplayed by the playback device 110 c while another user is preparing foodin the kitchen 101 h and listening to classical music played by theplayback device 110 b. In another example, a playback zone may play thesame audio content in synchrony with another playback zone. Forinstance, the user may be in the office 101 e listening to the playbackdevice 110 f playing back the same hip hop music being played back byplayback device 110 c on the patio 101 i. In some aspects, the playbackdevices 110 c and 110 f play back the hip hop music in synchrony suchthat the user perceives that the audio content is being playedseamlessly (or at least substantially seamlessly) while moving betweendifferent playback zones. Additional details regarding audio playbacksynchronization among playback devices and/or zones can be found, forexample, in U.S. Pat. No. 8,234,395 entitled, “System and method forsynchronizing operations among a plurality of independently clockeddigital data processing devices,” which is incorporated herein byreference in its entirety.

a. Suitable Media Playback System

FIG. 1B is a schematic diagram of the media playback system 100 and acloud network 102. For ease of illustration, certain devices of themedia playback system 100 and the cloud network 102 are omitted fromFIG. 1B. One or more communication links 103 (referred to hereinafter as“the links 103”) communicatively couple the media playback system 100and the cloud network 102.

The links 103 can comprise, for example, one or more wired networks, oneor more wireless networks, one or more wide area networks (WAN), one ormore local area networks (LAN), one or more personal area networks(PAN), one or more telecommunication networks (e.g., one or more GlobalSystem for Mobiles (GSM) networks, Code Division Multiple Access (CDMA)networks, Long-Term Evolution (LTE) networks, 5G communication networknetworks, and/or other suitable data transmission protocol networks),etc. The cloud network 102 is configured to deliver media content (e.g.,audio content, video content, photographs, social media content) to themedia playback system 100 in response to a request transmitted from themedia playback system 100 via the links 103. In some embodiments, thecloud network 102 is further configured to receive data (e.g. voiceinput data) from the media playback system 100 and correspondinglytransmit commands and/or media content to the media playback system 100.

The cloud network 102 comprises computing devices 106 (identifiedseparately as a first computing device 106 a, a second computing device106 b, and a third computing device 106 c). The computing devices 106can comprise individual computers or servers, such as, for example, amedia streaming service server storing audio and/or other media content,a voice service server, a social media server, a media playback systemcontrol server, etc. In some embodiments, one or more of the computingdevices 106 comprise modules of a single computer or server. In certainembodiments, one or more of the computing devices 106 comprise one ormore modules, computers, and/or servers. Moreover, while the cloudnetwork 102 is described above in the context of a single cloud network,in some embodiments the cloud network 102 comprises a plurality of cloudnetworks comprising communicatively coupled computing devices.Furthermore, while the cloud network 102 is shown in FIG. 1B as havingthree of the computing devices 106, in some embodiments, the cloudnetwork 102 comprises fewer (or more than) three computing devices 106.

The media playback system 100 is configured to receive media contentfrom the networks 102 via the links 103. The received media content cancomprise, for example, a Uniform Resource Identifier (URI) and/or aUniform Resource Locator (URL). For instance, in some examples, themedia playback system 100 can stream, download, or otherwise obtain datafrom a URI or a URL corresponding to the received media content. Anetwork 104 communicatively couples the links 103 and at least a portionof the devices (e.g., one or more of the playback devices 110, NMDs 120,and/or control devices 130) of the media playback system 100. Thenetwork 104 can include, for example, a wireless network (e.g., a WiFinetwork, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitablewireless communication protocol network) and/or a wired network (e.g., anetwork comprising Ethernet, Universal Serial Bus (USB), and/or anothersuitable wired communication). As those of ordinary skill in the artwill appreciate, as used herein, “WiFi” can refer to several differentcommunication protocols including, for example, Institute of Electricaland Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj,802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz(GHz), 5 GHz, and/or another suitable frequency.

In some embodiments, the network 104 comprises a dedicated communicationnetwork that the media playback system 100 uses to transmit messagesbetween individual devices and/or to transmit media content to and frommedia content sources (e.g., one or more of the computing devices 106).In certain embodiments, the network 104 is configured to be accessibleonly to devices in the media playback system 100, thereby reducinginterference and competition with other household devices. In otherembodiments, however, the network 104 comprises an existing householdcommunication network (e.g., a household WiFi network). In someembodiments, the links 103 and the network 104 comprise one or more ofthe same networks. In some aspects, for example, the links 103 and thenetwork 104 comprise a telecommunication network (e.g., an LTE network,a 5G network). Moreover, in some embodiments, the media playback system100 is implemented without the network 104, and devices comprising themedia playback system 100 can communicate with each other, for example,via one or more direct connections, PANs, telecommunication networks,and/or other suitable communication links.

In some embodiments, audio content sources may be regularly added orremoved from the media playback system 100. In some embodiments, forexample, the media playback system 100 performs an indexing of mediaitems when one or more media content sources are updated, added to,and/or removed from the media playback system 100. The media playbacksystem 100 can scan identifiable media items in some or all foldersand/or directories accessible to the playback devices 110, and generateor update a media content database comprising metadata (e.g., title,artist, album, track length) and other associated information (e.g.,URIs, URLs) for each identifiable media item found. In some embodiments,for example, the media content database is stored on one or more of theplayback devices 110, network microphone devices 120, and/or controldevices 130.

In the illustrated embodiment of FIG. 1B, the playback devices 110 l and110 m comprise a group 107 a. The playback devices 110 l and 110 m canbe positioned in different rooms in a household and be grouped togetherin the group 107 a on a temporary or permanent basis based on user inputreceived at the control device 130 a and/or another control device 130in the media playback system 100. When arranged in the group 107 a, theplayback devices 110 l and 110 m can be configured to play back the sameor similar audio content in synchrony from one or more audio contentsources. In certain embodiments, for example, the group 107 a comprisesa bonded zone in which the playback devices 110 l and 110 m compriseleft audio and right audio channels, respectively, of multi-channelaudio content, thereby producing or enhancing a stereo effect of theaudio content. In some embodiments, the group 107 a includes additionalplayback devices 110. In other embodiments, however, the media playbacksystem 100 omits the group 107 a and/or other grouped arrangements ofthe playback devices 110.

The media playback system 100 includes the NMDs 120 a and 120 d, eachcomprising one or more microphones configured to receive voiceutterances from a user. In the illustrated embodiment of FIG. 1B, theNMD 120 a is a standalone device and the NMD 120 d is integrated intothe playback device 110 n. The NMD 120 a, for example, is configured toreceive voice input 121 from a user 123. In some embodiments, the NMD120 a transmits data associated with the received voice input 121 to avoice assistant service (VAS) configured to (i) process the receivedvoice input data and (ii) transmit a corresponding command to the mediaplayback system 100. In some aspects, for example, the computing device106 c comprises one or more modules and/or servers of a VAS (e.g., a VASoperated by one or more of SONOS®, AMAZON®, GOOGLE® APPLE®, MICROSOFT®).The computing device 106 c can receive the voice input data from the NMD120 a via the network 104 and the links 103. In response to receivingthe voice input data, the computing device 106 c processes the voiceinput data (i.e., “Play Hey Jude by The Beatles”), and determines thatthe processed voice input includes a command to play a song (e.g., “HeyJude”). The computing device 106 c accordingly transmits commands to themedia playback system 100 to play back “Hey Jude” by the Beatles from asuitable media service (e.g., via one or more of the computing devices106) on one or more of the playback devices 110.

b. Suitable Playback Devices

FIG. 1C is a block diagram of the playback device 110 a comprising aninput/output 111. The input/output 111 can include an analog I/O 111 a(e.g., one or more wires, cables, and/or other suitable communicationlinks configured to carry analog signals) and/or a digital I/O 111 b(e.g., one or more wires, cables, or other suitable communication linksconfigured to carry digital signals). In some embodiments, the analogI/O 111 a is an audio line-in input connection comprising, for example,an auto-detecting 3.5 mm audio line-in connection. In some embodiments,the digital I/O 111 b comprises a Sony/Philips Digital Interface Format(S/PDIF) communication interface and/or cable and/or a Toshiba Link(TOSLINK) cable. In some embodiments, the digital I/O 111 b comprises anHigh-Definition Multimedia Interface (HDMI) interface and/or cable. Insome embodiments, the digital I/O 111 b includes one or more wirelesscommunication links comprising, for example, a radio frequency (RF),infrared, WiFi, Bluetooth, or another suitable communication protocol.In certain embodiments, the analog I/O 111 a and the digital 111 bcomprise interfaces (e.g., ports, plugs, jacks) configured to receiveconnectors of cables transmitting analog and digital signals,respectively, without necessarily including cables.

The playback device 110 a, for example, can receive media content (e.g.,audio content comprising music and/or other sounds) from a local audiosource 105 via the input/output 111 (e.g., a cable, a wire, a PAN, aBluetooth connection, an ad hoc wired or wireless communication network,and/or another suitable communication link). The local audio source 105can comprise, for example, a mobile device (e.g., a smartphone, atablet, a laptop computer) or another suitable audio component (e.g., atelevision, a desktop computer, an amplifier, a phonograph, a Blu-rayplayer, a memory storing digital media files). In some aspects, thelocal audio source 105 includes local music libraries on a smartphone, acomputer, a networked-attached storage (NAS), and/or another suitabledevice configured to store media files. In certain embodiments, one ormore of the playback devices 110, NMDs 120, and/or control devices 130comprise the local audio source 105. In other embodiments, however, themedia playback system omits the local audio source 105 altogether. Insome embodiments, the playback device 110 a does not include aninput/output 111 and receives all audio content via the network 104.

The playback device 110 a further comprises electronics 112, a userinterface 113 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens), and one or more transducers 114(referred to hereinafter as “the transducers 114”). The electronics 112is configured to receive audio from an audio source (e.g., the localaudio source 105) via the input/output 111, one or more of the computingdevices 106 a-c via the network 104 (FIG. 1B)), amplify the receivedaudio, and output the amplified audio for playback via one or more ofthe transducers 114. In some embodiments, the playback device 110 aoptionally includes one or more microphones 115 (e.g., a singlemicrophone, a plurality of microphones, a microphone array) (hereinafterreferred to as “the microphones 115”). In certain embodiments, forexample, the playback device 110 a having one or more of the optionalmicrophones 115 can operate as an NMD configured to receive voice inputfrom a user and correspondingly perform one or more operations based onthe received voice input.

In the illustrated embodiment of FIG. 1C, the electronics 112 compriseone or more processors 112 a (referred to hereinafter as “the processors112 a”), memory 112 b, software components 112 c, a network interface112 d, one or more audio processing components 112 g (referred tohereinafter as “the audio components 112 g”), one or more audioamplifiers 112 h (referred to hereinafter as “the amplifiers 112 h”),and power 112 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 112 optionally include one or more othercomponents 112 j (e.g., one or more sensors, video displays,touchscreens, battery charging bases).

The processors 112 a can comprise clock-driven computing component(s)configured to process data, and the memory 112 b can comprise acomputer-readable medium (e.g., a tangible, non-transitorycomputer-readable medium, data storage loaded with one or more of thesoftware components 112 c) configured to store instructions forperforming various operations and/or functions. The processors 112 a areconfigured to execute the instructions stored on the memory 112 b toperform one or more of the operations. The operations can include, forexample, causing the playback device 110 a to retrieve audio data froman audio source (e.g., one or more of the computing devices 106 a-c(FIG. 1B)), and/or another one of the playback devices 110. In someembodiments, the operations further include causing the playback device110 a to send audio data to another one of the playback devices 110 aand/or another device (e.g., one of the NMDs 120). Certain embodimentsinclude operations causing the playback device 110 a to pair withanother of the one or more playback devices 110 to enable amulti-channel audio environment (e.g., a stereo pair, a bonded zone).

The processors 112 a can be further configured to perform operationscausing the playback device 110 a to synchronize playback of audiocontent with another of the one or more playback devices 110. As thoseof ordinary skill in the art will appreciate, during synchronousplayback of audio content on a plurality of playback devices, a listenerwill preferably be unable to perceive time-delay differences betweenplayback of the audio content by the playback device 110 a and the otherone or more other playback devices 110. Additional details regardingaudio playback synchronization among playback devices can be found, forexample, in U.S. Pat. No. 8,234,395, which was incorporated by referenceabove.

In some embodiments, the memory 112 b is further configured to storedata associated with the playback device 110 a, such as one or morezones and/or zone groups of which the playback device 110 a is a member,audio sources accessible to the playback device 110 a, and/or a playbackqueue that the playback device 110 a (and/or another of the one or moreplayback devices) can be associated with. The stored data can compriseone or more state variables that are periodically updated and used todescribe a state of the playback device 110 a. The memory 112 b can alsoinclude data associated with a state of one or more of the other devices(e.g., the playback devices 110, NMDs 120, control devices 130) of themedia playback system 100. In some aspects, for example, the state datais shared during predetermined intervals of time (e.g., every 5 seconds,every 10 seconds, every 60 seconds) among at least a portion of thedevices of the media playback system 100, so that one or more of thedevices have the most recent data associated with the media playbacksystem 100.

The network interface 112 d is configured to facilitate a transmissionof data between the playback device 110 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). The network interface 112 d is configured to transmit andreceive data corresponding to media content (e.g., audio content, videocontent, text, photographs) and other signals (e.g., non-transitorysignals) comprising digital packet data including an Internet Protocol(IP)-based source address and/or an IP-based destination address. Thenetwork interface 112 d can parse the digital packet data such that theelectronics 112 properly receives and processes the data destined forthe playback device 110 a.

In the illustrated embodiment of FIG. 1C, the network interface 112 dcomprises one or more wireless interfaces 112 e (referred to hereinafteras “the wireless interface 112 e”). The wireless interface 112 e (e.g.,a suitable interface comprising one or more antennae) can be configuredto wirelessly communicate with one or more other devices (e.g., one ormore of the other playback devices 110, NMDs 120, and/or control devices130) that are communicatively coupled to the network 104 (FIG. 1B) inaccordance with a suitable wireless communication protocol (e.g., WiFi,Bluetooth, LTE). In some embodiments, the network interface 112 doptionally includes a wired interface 112 f (e.g., an interface orreceptacle configured to receive a network cable such as an Ethernet, aUSB-A, USB-C, and/or Thunderbolt cable) configured to communicate over awired connection with other devices in accordance with a suitable wiredcommunication protocol. In certain embodiments, the network interface112 d includes the wired interface 112 f and excludes the wirelessinterface 112 e. In some embodiments, the electronics 112 excludes thenetwork interface 112 d altogether and transmits and receives mediacontent and/or other data via another communication path (e.g., theinput/output 111).

The audio components 112 g are configured to process and/or filter datacomprising media content received by the electronics 112 (e.g., via theinput/output 111 and/or the network interface 112 d) to produce outputaudio signals. In some embodiments, the audio processing components 112g comprise, for example, one or more digital-to-analog converters (DAC),audio preprocessing components, audio enhancement components, a digitalsignal processors (DSPs), and/or other suitable audio processingcomponents, modules, circuits, etc. In certain embodiments, one or moreof the audio processing components 112 g can comprise one or moresubcomponents of the processors 112 a. In some embodiments, theelectronics 112 omits the audio processing components 112 g. In someaspects, for example, the processors 112 a execute instructions storedon the memory 112 b to perform audio processing operations to producethe output audio signals.

The amplifiers 112 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 112 g and/orthe processors 112 a. The amplifiers 112 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 114. In someembodiments, for example, the amplifiers 112 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 112 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 112 h correspond toindividual ones of the transducers 114. In other embodiments, however,the electronics 112 includes a single one of the amplifiers 112 hconfigured to output amplified audio signals to a plurality of thetransducers 114. In some other embodiments, the electronics 112 omitsthe amplifiers 112 h.

The transducers 114 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 112 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 114 can comprise a singletransducer. In other embodiments, however, the transducers 114 comprisea plurality of audio transducers. In some embodiments, the transducers114 comprise more than one type of transducer. For example, thetransducers 114 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters). As used herein, “low frequency” cangenerally refer to audible frequencies below about 500 Hz, “mid-rangefrequency” can generally refer to audible frequencies between about 500Hz and about 2 kHz, and “high frequency” can generally refer to audiblefrequencies above 2 kHz. In certain embodiments, however, one or more ofthe transducers 114 comprise transducers that do not adhere to theforegoing frequency ranges. For example, one of the transducers 114 maycomprise a mid-woofer transducer configured to output sound atfrequencies between about 200 Hz and about 5 kHz.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including, for example, a “SONOS ONE,”“PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “PLAYBASE,” “CONNECT:AMP,”“CONNECT,” and “SUB.” Other suitable playback devices may additionallyor alternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, one of ordinary skilled inthe art will appreciate that a playback device is not limited to theexamples described herein or to SONOS product offerings. In someembodiments, for example, one or more playback devices 110 compriseswired or wireless headphones (e.g., over-the-ear headphones, on-earheadphones, in-ear earphones). In other embodiments, one or more of theplayback devices 110 comprise a docking station and/or an interfaceconfigured to interact with a docking station for personal mobile mediaplayback devices. In certain embodiments, a playback device may beintegral to another device or component such as a television, a lightingfixture, or some other device for indoor or outdoor use. In someembodiments, a playback device omits a user interface and/or one or moretransducers. For example, FIG. 1D is a block diagram of a playbackdevice 110 p comprising the input/output 111 and electronics 112 withoutthe user interface 113 or transducers 114.

FIG. 1E is a block diagram of a bonded playback device 110 q comprisingthe playback device 110 a (FIG. 1C) sonically bonded with the playbackdevice 110 i (e.g., a subwoofer) (FIG. 1A). In the illustratedembodiment, the playback devices 110 a and 110 i are separate ones ofthe playback devices 110 housed in separate enclosures. In someembodiments, however, the bonded playback device 110 q comprises asingle enclosure housing both the playback devices 110 a and 110 i. Thebonded playback device 110 q can be configured to process and reproducesound differently than an unbonded playback device (e.g., the playbackdevice 110 a of FIG. 1C) and/or paired or bonded playback devices (e.g.,the playback devices 110 l and 110 m of FIG. 1B). In some embodiments,for example, the playback device 110 a is full-range playback deviceconfigured to render low frequency, mid-range frequency, and highfrequency audio content, and the playback device 110 i is a subwooferconfigured to render low frequency audio content. In some aspects, theplayback device 110 a, when bonded with the first playback device, isconfigured to render only the mid-range and high frequency components ofa particular audio content, while the playback device 110 i renders thelow frequency component of the particular audio content. In someembodiments, the bonded playback device 110 q includes additionalplayback devices and/or another bonded playback device.

c. Suitable Network Microphone Devices (NMDs)

FIG. 1F is a block diagram of the NMD 120 a (FIGS. 1A and 1B). The NMD120 a includes one or more voice processing components 124 (hereinafter“the voice components 124”) and several components described withrespect to the playback device 110 a (FIG. 1C) including the processors112 a, the memory 112 b, and the microphones 115. The NMD 120 aoptionally comprises other components also included in the playbackdevice 110 a (FIG. 1C), such as the user interface 113 and/or thetransducers 114. In some embodiments, the NMD 120 a is configured as amedia playback device (e.g., one or more of the playback devices 110),and further includes, for example, one or more of the audio components112 g (FIG. 1C), the amplifiers 114, and/or other playback devicecomponents. In certain embodiments, the NMD 120 a comprises an Internetof Things (IoT) device such as, for example, a thermostat, alarm panel,fire and/or smoke detector, etc. In some embodiments, the NMD 120 acomprises the microphones 115, the voice processing 124, and only aportion of the components of the electronics 112 described above withrespect to FIG. 1B. In some aspects, for example, the NMD 120 a includesthe processor 112 a and the memory 112 b (FIG. 1B), while omitting oneor more other components of the electronics 112. In some embodiments,the NMD 120 a includes additional components (e.g., one or more sensors,cameras, thermometers, barometers, hygrometers).

In some embodiments, an NMD can be integrated into a playback device.FIG. 1G is a block diagram of a playback device 110 r comprising an NMD120 d. The playback device 110 r can comprise many or all of thecomponents of the playback device 110 a and further include themicrophones 115 and voice processing 124 (FIG. 1F). The playback device110 r optionally includes an integrated control device 130 c. Thecontrol device 130 c can comprise, for example, a user interface (e.g.,the user interface 113 of FIG. 1B) configured to receive user input(e.g., touch input, voice input) without a separate control device. Inother embodiments, however, the playback device 110 r receives commandsfrom another control device (e.g., the control device 130 a of FIG. 1B).

Referring again to FIG. 1F, the microphones 115 are configured toacquire, capture, and/or receive sound from an environment (e.g., theenvironment 101 of FIG. 1A) and/or a room in which the NMD 120 a ispositioned. The received sound can include, for example, vocalutterances, audio played back by the NMD 120 a and/or another playbackdevice, background voices, ambient sounds, etc. The microphones 115convert the received sound into electrical signals to produce microphonedata. The voice processing 124 receives and analyzes the microphone datato determine whether a voice input is present in the microphone data.The voice input can comprise, for example, an activation word followedby an utterance including a user request. As those of ordinary skill inthe art will appreciate, an activation word is a word or other audio cuethat signifying a user voice input. For instance, in querying theAMAZON® VAS, a user might speak the activation word “Alexa.” Otherexamples include “Ok, Google” for invoking the GOOGLE® VAS and “Hey,Siri” for invoking the APPLE® VAS.

After detecting the activation word, voice processing 124 monitors themicrophone data for an accompanying user request in the voice input. Theuser request may include, for example, a command to control athird-party device, such as a thermostat (e.g., NEST® thermostat), anillumination device (e.g., a PHILIPS HUE® lighting device), or a mediaplayback device (e.g., a Sonos® playback device). For example, a usermight speak the activation word “Alexa” followed by the utterance “setthe thermostat to 68 degrees” to set a temperature in a home (e.g., theenvironment 101 of FIG. 1A). The user might speak the same activationword followed by the utterance “turn on the living room” to turn onillumination devices in a living room area of the home. The user maysimilarly speak an activation word followed by a request to play aparticular song, an album, or a playlist of music on a playback devicein the home.

d. Suitable Control Devices

FIG. 1H is a partially schematic diagram of the control device 130 a(FIGS. 1A and 1B). As used herein, the term “control device” can be usedinterchangeably with “controller” or “control system.” Among otherfeatures, the control device 130 a is configured to receive user inputrelated to the media playback system 100 and, in response, cause one ormore devices in the media playback system 100 to perform an action(s) oroperation(s) corresponding to the user input. In the illustratedembodiment, the control device 130 a comprises a smartphone (e.g., aniPhone™, an Android phone) on which media playback system controllerapplication software is installed. In some embodiments, the controldevice 130 a comprises, for example, a tablet (e.g., an iPad™), acomputer (e.g., a laptop computer, a desktop computer), and/or anothersuitable device (e.g., a television, an automobile audio head unit, anIoT device). In certain embodiments, the control device 130 a comprisesa dedicated controller for the media playback system 100. In otherembodiments, as described above with respect to FIG. 1G, the controldevice 130 a is integrated into another device in the media playbacksystem 100 (e.g., one more of the playback devices 110, NMDs 120, and/orother suitable devices configured to communicate over a network).

The control device 130 a includes electronics 132, a user interface 133,one or more speakers 134, and one or more microphones 135. Theelectronics 132 comprise one or more processors 132 a (referred tohereinafter as “the processors 132 a”), a memory 132 b, softwarecomponents 132 c, and a network interface 132 d. The processor 132 a canbe configured to perform functions relevant to facilitating user access,control, and configuration of the media playback system 100. The memory132 b can comprise data storage that can be loaded with one or more ofthe software components executable by the processor 132 a to performthose functions. The software components 132 c can comprise applicationsand/or other executable software configured to facilitate control of themedia playback system 100. The memory 112 b can be configured to store,for example, the software components 132 c, media playback systemcontroller application software, and/or other data associated with themedia playback system 100 and the user.

The network interface 132 d is configured to facilitate networkcommunications between the control device 130 a and one or more otherdevices in the media playback system 100, and/or one or more remotedevices. In some embodiments, the network interface 132 is configured tooperate according to one or more suitable communication industrystandards (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G, LTE). The network interface 132 d can beconfigured, for example, to transmit data to and/or receive data fromthe playback devices 110, the NMDs 120, other ones of the controldevices 130, one of the computing devices 106 of FIG. 1B, devicescomprising one or more other media playback systems, etc. Thetransmitted and/or received data can include, for example, playbackdevice control commands, state variables, playback zone and/or zonegroup configurations. For instance, based on user input received at theuser interface 133, the network interface 132 d can transmit a playbackdevice control command (e.g., volume control, audio playback control,audio content selection) from the control device 130 a to one or more ofthe playback devices 100. The network interface 132 d can also transmitand/or receive configuration changes such as, for example,adding/removing one or more playback devices 100 to/from a zone,adding/removing one or more zones to/from a zone group, forming a bondedor consolidated player, separating one or more playback devices from abonded or consolidated player, among others.

The user interface 133 is configured to receive user input and canfacilitate ‘control of the media playback system 100. The user interface133 includes media content art 133 a (e.g., album art, lyrics, videos),a playback status indicator 133 b (e.g., an elapsed and/or remainingtime indicator), media content information region 133 c, a playbackcontrol region 133 d, and a zone indicator 133 e. The media contentinformation region 133 c can include a display of relevant information(e.g., title, artist, album, genre, release year) about media contentcurrently playing and/or media content in a queue or playlist. Theplayback control region 133 d can include selectable (e.g., via touchinput and/or via a cursor or another suitable selector) icons to causeone or more playback devices in a selected playback zone or zone groupto perform playback actions such as, for example, play or pause, fastforward, rewind, skip to next, skip to previous, enter/exit shufflemode, enter/exit repeat mode, enter/exit cross fade mode, etc. Theplayback control region 133 d may also include selectable icons tomodify equalization settings, playback volume, and/or other suitableplayback actions. In the illustrated embodiment, the user interface 133comprises a display presented on a touch screen interface of asmartphone (e.g., an iPhone™, an Android phone). In some embodiments,however, user interfaces of varying formats, styles, and interactivesequences may alternatively be implemented on one or more networkdevices to provide comparable control access to a media playback system.

The one or more speakers 134 (e.g., one or more transducers) can beconfigured to output sound to the user of the control device 130 a. Insome embodiments, the one or more speakers comprise individualtransducers configured to correspondingly output low frequencies,mid-range frequencies, and/or high frequencies. In some aspects, forexample, the control device 130 a is configured as a playback device(e.g., one of the playback devices 110). Similarly, in some embodimentsthe control device 130 a is configured as an NMD (e.g., one of the NMDs120), receiving voice commands and other sounds via the one or moremicrophones 135.

The one or more microphones 135 can comprise, for example, one or morecondenser microphones, electret condenser microphones, dynamicmicrophones, and/or other suitable types of microphones or transducers.In some embodiments, two or more of the microphones 135 are arranged tocapture location information of an audio source (e.g., voice, audiblesound) and/or configured to facilitate filtering of background noise.Moreover, in certain embodiments, the control device 130 a is configuredto operate as playback device and an NMD. In other embodiments, however,the control device 130 a omits the one or more speakers 134 and/or theone or more microphones 135. For instance, the control device 130 a maycomprise a device (e.g., a thermostat, an IoT device, a network device)comprising a portion of the electronics 132 and the user interface 133(e.g., a touch screen) without any speakers or microphones.

III. Example Systems and Methods for Calibrating a Playback Device

As discussed above, in some examples, a playback device is configured tocalibrate itself to account for an acoustic response of a room in whichthe playback device is located. The playback device performs thisself-calibration by leveraging a database that is populated withcalibration settings that were determined for a number of other playbackdevices. In some embodiments, the calibration settings stored in thedatabase are determined based on multi-location acoustic responses forthe rooms of the other playback devices.

FIG. 2A depicts an example environment for using a multi-locationacoustic response of a room to determine calibration settings for aplayback device. As shown in FIG. 2A, a playback device 210 a and anetwork device 230 are located in a room 201 a. The playback device 210a may be similar to any of the playback devices 110 depicted in FIGS.1A-1E and 1G, and the network device 230 may be similar to any of theNMDs 120 or controllers 130 depicted in FIGS. 1A-1B and 1F-1H. One orboth of the playback device 210 a and the network device 230 are incommunication, either directly or indirectly, with a computing device206. The computing device 206 may be similar to any of the computingdevices 106 depicted in FIG. 1B. For instance, the computing device 206may be a server located remotely from the room 201 a and connected tothe playback device 210 a and/or the network device 230 over a wired orwireless communication network.

In practice, the playback device 210 a outputs audio content via one ormore transducers (e.g., one or more speakers and/or speaker drivers) ofthe playback device 210 a. In one example, the audio content is outputusing a test signal or measurement signal representative of audiocontent that may be played by the playback device 210 a during regularuse by a user. Accordingly, the audio content may include content withfrequencies substantially covering a renderable frequency range of theplayback device 210 a or a frequency range audible to a human. In onecase, the audio content is output using an audio signal designedspecifically for use when calibrating playback devices such as theplayback device 210 a being calibrated in examples discussed herein. Inanother case, the audio content is an audio track that is a favorite ofa user of the playback device 210 a, or a commonly played audio track bythe playback device 210 a. Other examples are also possible.

While the playback device 210 a outputs the audio content, the networkdevice 230 moves to various locations within the room 201 a. Forinstance, the network device 230 may move between a first physicallocation and a second physical location within the room 201 a. As shownin FIG. 2A, the first physical location may be the point (a), and thesecond physical location may be the point (b). While moving from thefirst physical location (a) to the second physical location (b), thenetwork device 230 may traverse locations within the room 201 a whereone or more listeners may experience audio playback during regular useof the playback device 210 a. For instance, as shown, the room 201 aincludes a kitchen area and a dining area, and a path 208 between thefirst physical location (a) and the second physical location (b) coverslocations within the kitchen area and dining area where one or morelisteners may experience audio playback during regular use of theplayback device 210 a.

In some examples, movement of the network device 230 between the firstphysical location (a) and the second physical location (b) may beperformed by a user. In one case, a graphical display of the networkdevice 230 may provide an indication to move the network device 230within the room 201 a. For instance, the graphical display may displaytext, such as “While audio is playing, please move the network devicethrough locations within the playback zone where you or others may enjoymusic.” Other examples are also possible.

The network device 230 determines a multi-location acoustic response ofthe room 201 a. To facilitate this, while the network device 230 ismoving between physical locations within the room 201 a, the networkdevice 230 captures audio data representing reflections of the audiocontent output by the playback device 210 a in the room 201 a. Forinstance, the network device 230 may be a mobile device with a built-inmicrophone (e.g., microphone(s) 115 of network microphone device 120 a),and the network device 230 may use the built-in microphone to capturethe audio data representing reflections of the audio content at multiplelocations within the room 201 a.

The multi-location acoustic response is an acoustic response of the room201 a based on the detected audio data representing reflections of theaudio content at multiple locations in the room 201 a, such as at thefirst physical location (a) and the second physical location (b). Themulti-location acoustic response may be represented as a spectralresponse, spatial response, or temporal response, among others. Thespectral response may be an indication of how volume of audio soundcaptured by the microphone varies with frequency within the room 201 a.A power spectral density is an example representation of the spectralresponse. The spatial response may indicate how the volume of the audiosound captured by the microphone varies with direction and/or spatialposition in the room 201 a. The temporal response may be an indicationof how audio sound played by the playback device 210 a, e.g., an impulsesound or tone played by the playback device 210 a, changes within theroom 201 a. The change may be characterized as a reverberation, delay,decay, or phase change of the audio sound.

The responses may be represented in various forms. For instance, thespatial response and temporal responses may be represented as roomaverages. Additionally, or alternatively, the multi-location acousticresponse may be represented as a set of impulse responses or bi-quadfilter coefficients representative of the acoustic response, amongothers. Values of the multi-location acoustic response may berepresented in vector or matrix form.

Audio played by the playback device 210 a is adjusted based on themulti-location acoustic response of the room 201 a so as to offset orotherwise account for acoustics of the room 201 a indicated by themulti-location acoustic response. In particular, the multi-locationacoustic response is used to identify calibration settings, which mayinclude determining an audio processing algorithm. U.S. Pat. No.9,706,323, incorporated by reference above, discloses various audioprocessing algorithms, which are contemplated herein.

In some examples, determining the audio processing algorithm involvesdetermining an audio processing algorithm that, when applied to theplayback device 210 a, causes audio content output by the playbackdevice 210 a in the room 201 a to have a target frequency response. Forinstance, determining the audio processing algorithm may involvedetermining frequency responses at the multiple locations traversed bythe network device while moving within the room 201 a and determining anaudio processing algorithm that adjusts the frequency responses at thoselocations to more closely reflect target frequency responses. In oneexample, if one or more of the determined frequency responses has aparticular audio frequency that is more attenuated than otherfrequencies, then determining the audio processing algorithm may involvedetermining an audio processing algorithm that increases amplificationat the particular audio frequency. Other examples are possible as well.

In some examples, the audio processing algorithm takes the form of afilter or equalization. The filter or equalization may be applied by theplayback device 210 a (e.g., via audio processing components 112 g).Alternatively, the filter or equalization may be applied by anotherplayback device, the computing device 206, and/or the network device230, which then provides the processed audio content to the playbackdevice 210 a for output. The filter or equalization may be applied toaudio content played by the playback device 210 a until such time thatthe filter or equalization is changed or is no longer valid for the room201 a.

The audio processing algorithm may be stored in a database of thecomputing device 206 or may be calculated dynamically. For instance, insome examples, the network device 230 sends to the computing device 206the detected audio data representing reflections of the audio content atmultiple locations in the room 201 a, and receives, from the computingdevice 206, the audio processing algorithm after the computing device206 has determined the audio processing algorithm. In other examples,the network device 230 determines the audio processing algorithm basedon the detected audio data representing reflections of the audio contentat multiple locations in the room 201 a.

Further, while the network device 230 captures audio data at multiplelocations in the room 201 a for determining the multi-location acousticresponse of the room 201 a, the playback device 210 a concurrentlycaptures audio data at a stationary location for determining a localizedacoustic response of the room 201 a. To facilitate this, the playbackdevice 210 a may have one or more microphones, which may be fixed inlocation. For example, the one or more microphones may be co-located inor on the playback device 210 a (e.g., mounted in a housing of theplayback device) or be co-located in or on an NMD proximate to theplayback device 210 a. Additionally, the one or more microphones may beoriented in one or more directions. The one or more microphones detectaudio data representing reflections of the audio content output by theplayback device 210 a in the room 201 a, and this detected audio data isused to determine the localized acoustic response of the room 201 a.

The localized acoustic response is an acoustic response of the room 201a based on the detected audio data representing reflections of the audiocontent at a stationary location in the room. The stationary locationmay be at the one or more microphones located on or proximate to theplayback device 210 a, but could also be at the microphone of an NMD ora controller device proximate to the playback device 210 a.

The localized acoustic response may be represented as a spectralresponse, spatial response, or temporal response, among others. Thespectral response may be an indication of how volume of audio soundcaptured by the microphone varies with frequency within the room 201 a.A power spectral density is an example representation of the spectralresponse. The spatial response may indicate how the volume of the audiosound captured by the microphone varies with direction and/or spatialposition in the room 201 a. The temporal response may be an indicationof how audio sound played by the playback device 210 a, e.g., an impulsesound or tone played by the playback device 210 a, changes within theroom 201 a. The change may be characterized as a reverberation, delay,decay, or phase change of the audio sound. The spatial response andtemporal response may be represented as averages in some instances.Additionally, or alternatively, the localized acoustic response may berepresented as a set of impulse responses or bi-quad filter coefficientsrepresentative of the acoustic response, among others. Values of thelocalized acoustic response may be represented in vector or matrix form.

Similar to the multi-location acoustic response, the localized acousticresponse of the room 201 a may be used to determine a set of calibrationsettings for the playback device 210 a. As such, calibration settingsbased on a multi-location acoustic response are referred to herein as“multi-location calibration settings,” and calibration settings based ona localized acoustic response are referred to herein as “localizedcalibration settings.” Further, like the multi-location calibrationsettings, the localized calibration settings are configured to offset orotherwise account for acoustic characteristics of the room 201 a. Insome examples, the localized calibration settings, when applied to theplayback device 210 a, cause audio content output by the playback device210 a in the room 201 a to have a target frequency response. Forinstance, determining the localized calibration settings may involvedetermining an audio processing algorithm that adjusts a frequencyresponse detected at or near the playback device 210 a to more closelyreflect a target frequency response. In one example, if the detectedfrequency response has a particular audio frequency that is moreattenuated than other frequencies, then determining the localizedcalibration settings may involve determining an audio processingalgorithm that increases amplification at the particular audiofrequency. Other examples are possible as well.

Like the multi-location calibration settings, the localized calibrationsettings of the room 201 a may be determined in various ways. In onecase, the playback device 210 a determines the localized acousticresponse based on the detected audio data representing audio reflectionscaptured by the playback device 210 a within the room 201 a, and thenthe playback device 210 a determines the localized calibration settingsbased on the localized acoustic response of the room 201 a. In anothercase, the playback device 210 a sends the detected audio data to thenetwork device 230, the network device 230 determines the localizedacoustic response based on the detected audio data, and the networkdevice 230 determines the localized calibration settings based on thelocalized acoustic response. In yet another case, the playback device210 a or the network device 230 sends the detected audio data to thecomputing device 206, and the computing device 206 (or another deviceconnected to the computing device 206) determines the localized acousticresponse and the localized calibration settings.

Once the multi-location calibration settings for the playback device 210a and the localized acoustic response of the room 201 a are determined,this data is then provided to a computing device, such as computingdevice 206, for storage in a database. For instance, the network device230 may send the determined multi-location calibration settings to thecomputing device 206, and the playback device 210 a may send thelocalized acoustic response of the room 201 a to the computing device206. In other examples, the network device 230 or the playback device210 a sends both the determined multi-location calibration settings andthe localized acoustic response of the room 201 a to the computingdevice 206. Other examples are possible as well.

FIG. 2B depicts an example database 250 for storing both the determinedmulti-location calibration settings for the playback device 210 a andthe localized acoustic response of the room 201 a. The database 250 maybe stored on a computing device, such as computing device 206, locatedremotely from the playback device 210 a and/or from the network device230, or the database 250 may be stored on the playback device 210 aand/or the network device 230. The database 250 includes a number ofrecords, and each record includes data representing multi-locationcalibrations settings (identified as “settings 1” through “settings 5”)for various playback devices as well as room responses (identified as“response 1” through “response 5”), such as localized acousticresponses, associated with the multi-location calibration settings. Forthe purpose of illustration, the database 250 only depicts five records(numbered 1-5), but in practice should include many more than fiverecords to improve the accuracy of the calibration processes describedin further detail below.

When the computing device 206 receives data representing themulti-location calibration settings for the playback device 210 a anddata representing the localized acoustic response of the room 201 a, thecomputing device 206 stores the received data in a record of thedatabase 250. As an example, the computing device 206 stores thereceived data in record #1 of the database 250, such that “response 1”includes data representing the localized acoustic response of the room201 a, and “settings 1” includes data representing the multi-locationcalibration settings for the playback device 210 a. In some cases, thedatabase 250 also includes data representing respective multi-locationacoustic responses associated with the localized acoustic responses andthe corresponding multi-location calibration settings. For instance, ifrecord #1 of database 250 corresponds to playback device 210 a, then“response 1” may include data representing both the localized acousticresponse of the room 201 a and the multi-location acoustic response ofthe room 201 a.

As further shown, in some examples, the database 250 includes dataidentifying a type of a playback device associate with each record.Playback device “type” refers to a model or revision of a model, as wellas different models that are designed to produce similar audio output(e.g., playback devices with similar components), among other examples.The type of the playback device may be indicated when providing thecalibration settings and room response data to the database 250. As anexample, in addition to the network device 230 and/or the playbackdevice 210 a sending data representing the multi-location calibrationsettings for the playback device 210 a and data representing thelocalized acoustic response of the room 201 a to the computing device206, the network device 230 and/or the playback device 210 a also sendsdata representing a type of the playback device 210 a to the computingdevice. Examples of playback device types offered by Sonos, Inc.include, by way of illustration, various models of playback devices suchas a “SONOS ONE,” “PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “PLAYBASE,”“CONNECT:AMP,” “CONNECT,” and “SUB,” among others.

In some examples, the data identifying the type of the playback deviceadditionally or alternatively includes data identifying a configurationof the playback device. For instance, as described above in connectionwith FIG. 1E, a playback device may be a bonded or paired playbackdevice configured to process and reproduce sound differently than anunbonded or unpaired playback device. Accordingly, in some examples, thedata identifying the type of the playback device 210 a includes dataidentifying whether the playback device 210 a is in a bonded or pairedconfiguration.

By storing in the database 250 data identifying the type of the playbackdevice, the database 250 may be more quickly searched by filtering databased on playback device type, as described in further detail below.However, in some examples, the database 250 does not include dataidentifying the device type of the playback device associated with eachrecord.

Each record of the database 250 corresponds to a historical playbackdevice calibration process in which a particular playback device wascalibrated by determining calibration settings based on a multi-locationacoustic response, as described above in connection with FIG. 2A. Thecalibration processes are “historical” in the sense that they relate tomulti-location calibration settings and localized acoustic responsesdetermined for rooms with various types of acoustic characteristicspreviously determined and stored in the database 250. As additionaliterations of the calibration process are performed, the resultingmulti-location calibration settings and localized acoustic responses maybe added to the database 250.

Other playback devices may leverage the historical multi-locationcalibration settings and localized acoustic responses stored in thedatabase 250 in order to self-calibrate to account for the acousticresponses of the rooms in which they are located. In one example, aplayback device determines a localized acoustic response of a room inwhich the device is located, and the playback device queries thedatabase 250 to identify a record having a stored acoustic response thatis similar to the determined acoustic response. The playback device thenapplies to itself the multi-location calibration settings stored in thedatabase 250 that are associated with the identified record.

Efficacy of the applied calibration settings is influenced by a degreeof similarity between the identified stored acoustic response in thedatabase 250 and the determined acoustic response for the playbackdevice being calibrated. In particular, if the acoustic responses aresignificantly similar or identical, then the applied calibrationsettings are more likely to accurately offset or otherwise account foran acoustic response of the room in which the playback device beingcalibrated is located (e.g., by achieving or approaching a targetfrequency response in the room, as described above). On the other hand,if the acoustic responses are relatively dissimilar, then the appliedcalibration settings are less likely to accurately account for anacoustic response of the room in which the playback device beingcalibrated is located. Accordingly, populating the database 250 withrecords corresponding to a significantly large number of historicalcalibration processes may be desirable so as to increase the likelihoodof the database 250 including acoustic response data similar to anacoustic response of the room of the playback device presently beingcalibrated.

FIG. 2C depicts an example environment in which a playback device 210 bleverages the database 250 to perform a self-calibration process withoutdetermining a multi-location acoustic response of its room 201 b.

In one example, the self-calibration of the playback device 210 b may beinitiated when the playback device 210 b is being set up for the firsttime in the room 201 b, when the playback device 210 b first outputsmusic or some other audio content, or if the playback device 210 b hasbeen moved to a new location. For instance, if the playback device 210 bis moved to a new location, calibration of the playback device 210 b maybe initiated based on a detection of the movement (e.g., via a globalpositioning system (GPS), one or more accelerometers, or wireless signalstrength variations), or based on a user input indicating that theplayback device 210 b has moved to a new location (e.g., a change inplayback zone name associated with the playback device 210 b).

In another example, calibration of the playback device 210 b may beinitiated via a controller device, such as the controller device 130 adepicted in FIG. 1H. For instance, a user may access a controllerinterface for the playback device 210 b to initiate calibration of theplayback device 210 b. In one case, the user may access the controllerinterface, and select the playback device 210 b (or a group of playbackdevices that includes the playback device 210 b) for calibration. Insome cases, a calibration interface may be provided as part of aplayback device controller interface to allow a user to initiateplayback device calibration. Other examples are also possible.

Further, in some examples, calibration of the playback device 210 b isinitiated periodically, or after a threshold amount of time has elapsedafter a previous calibration, in order to account for changes to theenvironment of the playback device 210 b. For instance, a user maychange a layout of the room 201 b (e.g., by adding, removing, orrearranging furniture), thereby altering the acoustic response of theroom 201 b. As a result, any calibration settings applied to theplayback device 210 b before the room 201 b is altered may have areduced efficacy of accounting for, or offsetting, the altered acousticresponse of the room 201 b. Initiating calibration of the playbackdevice 210 b periodically, or after a threshold amount of time haselapsed after a previous calibration, can help address this issue byupdating the calibration settings at a later time (i.e., after the room201 b is altered) so that the calibration settings applied to theplayback device 210 b are based on the altered acoustic response of theroom 201 b.

Additionally, because calibration of the playback device 210 b involvesaccessing and retrieving calibration settings from the database 250, asdescribed in further detail below, initiating calibration of theplayback device 210 b periodically, or after a threshold amount of timehas elapsed after a previous calibration, may further improve alistening experience in the room 201 b by accounting for changes to thedatabase 250. For instance, as users continue to calibrate variousplayback devices in various rooms, the database 250 continues to beupdated with additional acoustic room responses and correspondingcalibration settings. As such, a newly added acoustic response (i.e., anacoustic response that is added to the database 250 after the playbackdevice 210 b has already been calibrated) may more closely resemble theacoustic response of the room 201 b. Thus, by initiating calibration ofthe playback device 210 b periodically, or after a threshold amount oftime has elapsed after a previous calibration, the calibration settingscorresponding to the newly added acoustic response may be applied to theplayback device 210 b. Accordingly, in some examples, the playbackdevice 210 b determines that at least a threshold amount of time haselapsed after the playback device 210 b has been calibrated, and,responsive to making such a determination, the playback device 210 binitiates a calibration process, such as the calibration processesdescribed below.

When performing the calibration process, the playback device 210 boutputs audio content and determines a localized acoustic response ofits room 201 b similarly to how playback device 210 a determined alocalized acoustic response of room 201 a. For instance, the playbackdevice 210 b outputs audio content, which may include music or one ormore predefined tones, captures audio data representing reflections ofthe audio content within the room 201 b, and determines the localizedacoustic response based on the captured audio data.

Causing the playback device 210 b to output spectrally rich audiocontent during the calibration process may yield a more accuratelocalized acoustic response of the room 201 b. Thus, in examples wherethe audio content includes predefined tones, the playback device 210 bmay output predefined tones over a range of frequencies for determiningthe localized acoustic response of the room 201 b. And in examples wherethe audio content includes music, such as music played during normal useof the playback device 210 b, the playback device 210 b may determinethe localized acoustic response based on audio data that is capturedover an extended period of time. For instance, as the playback device210 b outputs music, the playback device 210 b may continue to captureaudio data representing reflections of the output music within the room201 b until a threshold amount of data at a threshold amount offrequencies is captured. Depending on the spectral content of the outputmusic, the playback device 210 b may capture the reflected audio dataover the course of multiple songs, for instance, in order for theplayback device 210 b to have captured the threshold amount of data atthe threshold amount of frequencies. In this manner, the playback device210 b gradually learns the localized acoustic response of the room 201b, and once a threshold confidence in understanding of the localizedacoustic response of the room 201 b is met, then the playback device 210b uses the localized acoustic response of the room 201 b to determinecalibration settings for the playback device 210 b, as described infurther detail below.

The playback device 210 b may output the audio content at various volumelevels. For instance, if audio characteristics such as acceptable volumeranges of the playback device 210 b are known, then the playback device210 b or a controller device, such as the controller 130 a depicted inFIG. 1H, in communication with the playback device 210 b may cause theplayback device 210 b to output the audio content at a volume that fallswithin the acceptable volume range of the playback device 210 b.However, there may be circumstances in which the acceptable volume rangeof the playback device 210 b is not known. For instance, the playbackdevice 210 b may include an amplifier, such as the “CONNECT:AMP,”offered by Sonos, Inc., configured to output audio via connection toexternal speakers with unknown audio characteristics. Without knowingthe audio characteristics of the speakers, the playback device 210 bcould damage the speakers by attempting to drive the speakers with toohigh electrical current.

The above issue may be addressed in various ways. For instance, in someexamples, the playback device 210 b is configured to apply a limit tothe output volume or to the driver current. The limit may be set to aconservative value that is safe for most or virtually all speakers. Insome embodiments, a user inputs into a controller device, for instance,information identifying or characterizing the speakers of the playbackdevice 210 b. The information may include a manufacturer and/or modelnumber of the speakers, a size of the speakers, a maximum rated currentor wattage of the speakers, or any other information that could be usedto characterize the audio capabilities of the speakers. The controllerthen uses the input information to set an appropriate output volume ofthe playback device 210 b. In some embodiments, the playback device 210b is configured to measure an impedance curve of the speakers, and theplayback device 210 b or the controller device sets the output volume ofthe playback device 210 b based on the measured impedance curve.

In some embodiments, the playback device 210 b varies the volume of theaudio content while the playback device 210 b outputs the audio content.In one example, the playback device 210 b outputs the audio content at afirst, lower volume and increases the volume of the audio content to asecond, higher volume. The increase may be a gradual increase over time(i.e., over a first portion of the time period in which the playbackdevice is outputting the audio content).

The playback device 210 b may determine when to stop increasing thevolume based on various characteristics, such as a signal-to-noise ratio(SNR) of audio detected by the playback device 210 b while outputtingthe audio content. A determined acoustic room response may be moreaccurate if the audio used for determining the room response has a highSNR. Thus, in some examples, the playback device 210 b uses itsmicrophone to capture audio data representing the output audio contentwithin the room 201 b, and the playback device 210 b determines an SNRof the captured audio data. If the determined SNR is below a thresholdSNR, then the playback device 210 b increases the volume of the outputaudio content. The playback device 210 b continues to increase thevolume of the output audio content until the determined SNR exceeds thethreshold SNR value. Similarly, in order to avoid outputting excessivelyloud audio content, in some embodiments the playback device 210 bdecreases the volume of the output audio content responsive todetermining that the SNR of the captured audio exceeds the threshold SNRvalue by a predetermined amount.

While outputting the audio content, the playback device 210 b uses oneor more stationary microphones, which may be disposed in or on a housingof the playback device 210 b or may be co-located in or on an NMDproximate to the playback device 210 b, to capture audio datarepresenting reflections of the audio content in the room 201 b. Theplayback device 210 b then uses the captured audio data to determine thelocalized acoustic response of the room 201 b. In line with thediscussion above, the localized acoustic response may include a spectralresponse, spatial response, or temporal response, among others, and thelocalized acoustic response may be represented in vector or matrix form.

In some embodiments, determining the localized acoustic response of theroom 201 b involves accounting for a self-response of the playbackdevice 210 b or of a microphone of the playback device 210 b, forexample, by processing the captured audio data representing reflectionsof the audio content in the room 201 b so that the captured audio datareduces or excludes the playback device's native influence on the audioreflections.

In one example, the self-response of the playback device 210 b isdetermined in an anechoic chamber, or is otherwise known based on aself-response of a similar playback device being determined in ananechoic chamber. In the anechoic chamber, audio content output by theplayback device 210 b is inhibited from reflecting back toward theplayback device 210 b, so that audio captured by a microphone of theplayback device 210 b is indicative of the self-response of the playbackdevice 210 b or of the microphone of the playback device 210 b. Knowingthe self-response of the playback device 210 b or of the microphone ofthe playback device 210 b, the playback device 210 offsets such aself-response from the captured audio data representing reflections ofthe first audio content when determining the localized acoustic responseof the room 201 b.

Once the localized acoustic response of the room 201 b is known, theplayback device 210 b accesses the database 250 to determine a set ofcalibration settings to account for the acoustic response of the room201 b. For example, the playback device 210 b establishes a connectionwith the computing device 206 and with the database 250 of the computingdevice 206, and the playback device 210 b queries the database 250 for astored acoustic room response that corresponds to the determinedlocalized acoustic response of the room 201 b.

In some examples, querying the database 250 involves mapping thedetermined localized acoustic response of the room 201 b to a particularstored acoustic room response in the database 250 that satisfies athreshold similarity to the localized acoustic response of the room 201b. This mapping may involve comparing values of the localized acousticresponse to values of the stored acoustic room responses and determiningwhich of the stored acoustic room responses are similar to the localizedacoustic response.

For example, in implementations where the acoustic responses arerepresented as vectors, the mapping may involve determining distancesbetween the localized acoustic response vector and the stored acousticresponse vectors. In such a scenario, the stored acoustic responsevector having the smallest distance from the localized acoustic responsevector of the room 201 b may be identified as satisfying the thresholdsimilarity. In some examples, one or more values of the localizedacoustic response of the room 201 b may be averaged and compared tocorresponding averaged values of the stored acoustic responses of thedatabase 250. In such a scenario, the stored acoustic response havingaveraged values closest to the averaged values of the localized acousticresponse vector of the room 201 b may be identified as satisfying thethreshold similarity. Other examples are possible as well.

As shown, the room 201 b depicted in FIG. 2C and the room 201 a depictedin FIG. 2A are similarly shaped and have similar layouts. Further, theplayback device 210 b and the playback device 210 a are arranged insimilar positions in their respective rooms. As such, when the localizedroom response determined by playback device 210 b for room 201 b iscompared to the room responses stored in the database 250, the computingdevice 206 may determine that the localized room response determined byplayback device 210 a for room 201 a has at least a threshold similarityto the localized room response determined by playback device 210 b forroom 201 b.

In some examples, querying the database 250 involves querying only aportion of the database 250. For instance, as noted above, the database250 may identify a type or configuration of playback device for whicheach record of the database 250 is generated. Playback devices of thesame type or configuration may be more likely to have similar roomresponses and may be more likely to have compatible calibrationsettings. Accordingly, in some embodiments, when the playback device 210b queries the database 250 for comparing the localized acoustic responseof the room 201 b to the stored room responses of the database 250, theplayback device 210 b might only compare the localized acoustic responseof the room 201 b to stored room responses associated with playbackdevices of the same type or configuration as the playback device 210 b.

Once a stored acoustic room response of the database 250 is determinedto be threshold similar to the localized acoustic response of the room201 b, then the playback device 210 b identifies a set of calibrationsettings associated with the threshold similar stored acoustic roomresponse. For instance, as shown in FIG. 2B, each stored acoustic roomresponse is included as part of a record that also includes a set ofcalibration settings designed to account for the room response. As such,the playback device 210 b retrieves, or otherwise obtains from thedatabase 250, the set of calibration settings that share a record withthe threshold similar stored acoustic room response and applies the setof calibration settings to itself.

After applying the obtained calibration settings to itself, the playbackdevice 210 b outputs, via its one or more transducers, second audiocontent using the applied calibration settings. Even though the appliedcalibration settings were determined for a different playback devicecalibrated in a different room, the localized acoustic response of theroom 201 b is similar enough to the stored acoustic response that thesecond audio content is output in a manner that at least partiallyaccounts for the acoustics of the room 201 b. For instance, with theapplied calibration settings, the second audio content output by theplayback device 210 b may have a frequency response, at one or morelocations in the room 201 b, that is closer to a target frequencyresponse than the first audio content.

In line with the discussion above, the playback device 210 b (or someother network device in communication with the playback device 210 b)may determine localized calibration settings based on the localizedacoustic response. Accordingly, in some examples, before or whilequerying the database 250 for multi-location calibration settings, theplayback device 210 b determines localized calibration settings based onthe localized acoustic response of the room 201 b and applies thedetermined localized calibration settings to itself. And if the playbackdevice 210 b successfully queries the database 250 for multi-locationcalibration settings by mapping the determined localized acousticresponse of the room 201 b to a particular stored acoustic room responsein the database 250 as described above, then the playback device 210 btransitions from applying the localized calibration settings to applyingthe multi-location calibration settings retrieved from the database 250.

FIG. 3A shows an example embodiment of a method 300 for establishing adatabase of calibration settings for playback devices, and FIG. 3B showsan example embodiment of a method 320 for calibrating a playback deviceusing the database established according to method 300. Methods 300 and320 can be implemented by any of the playback devices disclosed and/ordescribed herein, or any other playback device now known or laterdeveloped.

Various embodiments of methods 300 and 320 include one or moreoperations, functions, and actions illustrated by blocks 302 through 312and blocks 322 through 334. Although the blocks are illustrated insequential order, these blocks may also be performed in parallel, and/orin a different order than the order disclosed and described herein.Also, the various blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon a desired implementation.

In addition, for the methods 300 and 320 and for other processes andmethods disclosed herein, the flowcharts show functionality andoperation of one possible implementation of some embodiments. In thisregard, each block may represent a module, a segment, or a portion ofprogram code, which includes one or more instructions executable by oneor more processors for implementing specific logical functions or stepsin the process. The program code may be stored on any type of computerreadable medium, for example, such as a storage device including a diskor hard drive. The computer readable medium may include non-transitorycomputer readable media, for example, such as tangible, non-transitorycomputer-readable media that stores data for short periods of time likeregister memory, processor cache, and Random Access Memory (RAM). Thecomputer readable medium may also include non-transitory media, such assecondary or persistent long term storage, like read only memory (ROM),optical or magnetic disks, compact-disc read only memory (CD-ROM), forexample. The computer readable media may also be any other volatile ornon-volatile storage systems. The computer readable medium may beconsidered a computer readable storage medium, for example, or atangible storage device. In addition, for the methods 300 and 320 andfor other processes and methods disclosed herein, each block in FIGS. 3Aand 3B may represent circuitry that is wired to perform the specificlogical functions in the process.

Method 300 involves populating a database with a plurality of sets ofstored audio calibration settings, each set associated with a respectivestored acoustic room response of a plurality of stored acoustic roomresponses. The plurality of sets of stored audio calibration settingsand the plurality of stored acoustic room responses are determined basedon multiple media playback systems each performing a respective audiocalibration process and a respective acoustic room responsedetermination process represented by method 300.

Method 300 begins at block 302, which involves a respective playbackdevice outputting respective audio content via one or more transducers(e.g., one or more speakers and/or speaker drivers) within a respectiveroom. In line with the discussion above, the audio content may includecontent with frequencies substantially covering a renderable frequencyrange of the respective playback device or a frequency range audible toa human. In one case, the audio content is output using an audio signalcreated specifically for use when calibrating playback devices, such asthe respective playback device. In another case, the audio content is anaudio track that is a favorite of a user of the respective playbackdevice, or a commonly played audio track by the respective playbackdevice. Other examples are also possible.

At block 304, method 300 involves, while the respective playback deviceoutputs the respective audio content, capturing, via a microphone of arespective mobile device in communication with the respective playbackdevice, first respective audio data representing reflections of therespective audio content in the respective room while the respectivemobile device is moving from a first physical location to a secondphysical location within the respective room.

At block 306, method 300 involves, while the respective playback deviceoutputs the respective audio content, capturing, via a microphonedisposed in a housing of the respective playback device, secondrespective audio data representing reflections of the respective audiocontent in the respective room.

At block 308, method 300 involves the respective playback device usingthe first respective audio data to determine a set of audio calibrationsettings for the respective playback device.

At block 310, method 300 involves the respective playback device usingthe second respective audio data to determine an acoustic response ofthe respective room.

At block 312, method 300 involves storing in the database the determinedset of audio calibration settings for the respective playback device aswell as the determined acoustic response of the respective room.

Turning now to FIG. 3B, method 320 involves a playback device using adatabase that is populated with a plurality of sets of stored audiocalibration settings and associated sets of stored acoustic roomresponses to calibrate the playback device so that the audio output bythe playback device accounts for the acoustics of a room in which theplayback device is located. In some examples, the database used inmethod 320 is populated by a plurality of playback devices performingmethod 300.

Method 320 begins at block 322, which involves a playback deviceoutputting first audio content via one or more transducers (e.g., one ormore speakers and/or speaker drivers) of the playback device. In someexamples, the first audio content is the same audio content output bythe respective playback device at block 302 in method 300. However, inother examples, the first audio content is different than the audiocontent output by the respective playback device at block 302 in method300.

In some embodiments, the playback device outputting the first audiocontent involves gradually increasing a volume level of the playbackdevice while outputting the first audio content. Further, in someembodiments, method 320 further involves, while outputting the firstaudio content, measuring a signal-to-noise ratio of the first audiocontent to environmental noise in the room in which the playback deviceis located, and, when the signal-to-noise ratio exceeds a thresholdvalue for calibration, ceasing to increase the volume level of theplayback device and continuing to output the first audio content at thecurrent volume level.

At block 324, method 320 involves capturing, via a microphone of theplayback device, audio data representing reflections of the first audiocontent within a room in which the playback device is located. As notedabove, instead of being moved around the room, the microphone of theplayback device is disposed in or on a housing of the playback device oris co-located in or on an NMD proximate to the playback device.

At block 326, method 320 involves, based on the captured audio data,determining an acoustic response of the room in which the playbackdevice is located. In some embodiments, a self-response of the playbackdevice is pre-determined in an anechoic chamber, and determining theacoustic response of the room in which the playback device is locatedinvolves offsetting the self-response of the playback device from thecaptured audio data representing reflections of the first audio content.Further, in some embodiments, a self-response of the playback device'smicrophone is pre-determined in an anechoic chamber, and determining theacoustic response of the room in which the playback device is locatedinvolves offsetting the self-response of the microphone from thecaptured audio data representing reflections of the first audio content.

At block 328, method 320 involves establishing a connection with adatabase comprising a plurality of sets of stored audio calibrationsettings, each set associated with a respective stored acoustic roomresponse of a plurality of stored acoustic room responses.

In line with the discussion above, the plurality of sets of stored audiocalibration settings are determined, in some embodiments, based onmultiple media playback systems each performing a respective audiocalibration process comprising (i) outputting, via a respective playbackdevice within a respective room that is different from the room in whichthe playback device is located, respective audio content, (ii) while therespective playback device outputs the respective audio content,capturing, via a microphone of a respective mobile device incommunication with the respective playback device, first respectiveaudio data representing reflections of the respective audio content inthe respective room while the respective mobile device is moving from afirst physical location to a second physical location within therespective room, and (iii) based on the first respective audio data,determining a set of audio calibration settings for the respectiveplayback device.

In some embodiments, determining the set of audio calibration settingsfor the respective playback device involves (i) determining audiocharacteristics of the respective room based on the first respectiveaudio data and (ii) determining respective audio calibration settingsfor the respective playback device that offset the determined audiocharacteristics of the respective room.

Further, in some embodiments, the plurality of stored acoustic roomresponses are determined based on the multiple media playback systemseach performing a respective acoustic room response determinationprocess comprising (i) while the respective playback device outputs therespective audio content, capturing, via a microphone disposed in ahousing of the respective playback device, second respective audio datarepresenting reflections of the respective audio content in therespective room, and (ii) based on the second respective audio data,determining an acoustic response of the respective room.

At block 330, method 320 involves querying the database for a storedacoustic room response that corresponds to the determined acousticresponse of the room in which the playback device is located. In someembodiments, querying the database for the stored acoustic room responseinvolves mapping the acoustic response of the room in which the playbackdevice is located to a particular stored acoustic room response in thedatabase that satisfies a threshold similarity to the acoustic responseof the room in which the playback device is located.

At block 332, method 320 involves, responsive to the query, applying tothe playback device a particular set of stored audio calibrationsettings associated with the stored acoustic room response thatcorresponds to the determined acoustic response of the room in which theplayback device is located.

At block 334, method 320 involves outputting, via the one or moretransducers of the playback device, second audio content using theparticular set of audio calibration settings associated with the storedacoustic room response that corresponds to the determined acousticresponse of the room in which the playback device is located.

IV. Conclusion

The above discussions relating to playback devices, controller devices,playback zone configurations, and media content sources provide onlysome examples of operating environments within which functions andmethods described below may be implemented. Other operating environmentsand configurations of media playback systems, playback devices, andnetwork devices not explicitly described herein may also be applicableand suitable for implementation of the functions and methods.

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyways) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

Additionally, references herein to “embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment can be included in at least one example embodiment of aninvention. The appearances of this phrase in various places in thespecification are not necessarily all referring to the same embodiment,nor are separate or alternative embodiments mutually exclusive of otherembodiments. As such, the embodiments described herein, explicitly andimplicitly understood by one skilled in the art, can be combined withother embodiments.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforegoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

What is claimed is:
 1. A playback device comprising: a microphone; aspeaker; one or more processors; and tangible, non-transitory,computer-readable media storing instructions executable by the one ormore processors to cause the playback device to perform operationscomprising: outputting, via the speaker, first audio content; capturing,via the microphone, audio data representing reflections of the firstaudio content within a room in which the playback device is located;based on the captured audio data, determining an acoustic response ofthe room in which the playback device is located; establishing aconnection with a database comprising a plurality of sets of storedaudio calibration settings, each set associated with a respective storedacoustic room response of a plurality of stored acoustic room responses;wherein the plurality of sets of stored audio calibration settings aredetermined based on multiple media playback systems each performing arespective audio calibration process comprising (i) outputting, via arespective playback device within a respective room that is differentfrom the room in which the playback device is located, respective audiocontent, (ii) while the respective playback device outputs therespective audio content, capturing, via a microphone of a respectivemobile device in communication with the respective playback device,first respective audio data representing reflections of the respectiveaudio content in the respective room while the respective mobile deviceis moving from a first physical location to a second physical locationwithin the respective room, and (iii) based on the first respectiveaudio data, determining a set of audio calibration settings for therespective playback device; wherein the plurality of stored acousticroom responses are determined based on the multiple media playbacksystems each performing a respective acoustic room responsedetermination process comprising (i) while the respective playbackdevice outputs the respective audio content, capturing, via a microphonedisposed in a housing of the respective playback device, secondrespective audio data representing reflections of the respective audiocontent in the respective room, and (ii) based on the second respectiveaudio data, determining an acoustic response of the respective room;querying the database for a stored acoustic room response thatcorresponds to the determined acoustic response of the room in which theplayback device is located; responsive to the query, applying to theplayback device a particular set of stored audio calibration settingsassociated with the stored acoustic room response that corresponds tothe determined acoustic response of the room in which the playbackdevice is located; and outputting, via the speaker, second audio contentusing the particular set of audio calibration settings associated withthe stored acoustic room response that corresponds to the determinedacoustic response of the room in which the playback device is located.2. The playback device of claim 1, wherein determining the set of audiocalibration settings for the respective playback device comprises: basedon the first respective audio data, determining audio characteristics ofthe respective room; and determining respective audio calibrationsettings for the respective playback device that offset the determinedaudio characteristics of the respective room.
 3. The playback device ofclaim 1, wherein querying the database comprises: mapping the acousticresponse of the room in which the playback device is located to aparticular stored acoustic room response in the database that satisfiesa threshold similarity to the acoustic response of the room in which theplayback device is located.
 4. The playback device of claim 1, wherein aself-response of the playback device is pre-determined in an anechoicchamber, and wherein determining the acoustic response of the room inwhich the playback device is located comprises offsetting theself-response of the playback device from the captured audio datarepresenting reflections of the first audio content.
 5. The playbackdevice of claim 1, wherein a self-response of the microphone ispre-determined in an anechoic chamber, and wherein determining theacoustic response of the room in which the playback device is locatedcomprises offsetting the self-response of the microphone from thecaptured audio data representing reflections of the first audio content.6. The playback device of claim 1, wherein outputting, via the speaker,the first audio content comprises gradually increasing a volume level ofthe playback device while outputting the first audio content, andwherein the operations further comprise: while outputting the firstaudio content, measuring a signal-to-noise ratio of the first audiocontent to environmental noise in the room in which the playback deviceis located; and when the signal-to-noise ratio exceeds a threshold valuefor calibration, ceasing to increase the volume level of the playbackdevice and continuing to output the first audio content at the currentvolume level.
 7. The playback device of claim 1, wherein the first audiocontent is different from the respective audio content.
 8. Tangible,non-transitory, computer-readable media storing instructions executableby one or more processors to cause a playback device to performoperations comprising: outputting, via a speaker of the playback device,first audio content; capturing, via a microphone of the playback device,audio data representing reflections of the first audio content within aroom in which the playback device is located; based on the capturedaudio data, determining an acoustic response of the room in which theplayback device is located; establishing a connection with a databasecomprising a plurality of sets of stored audio calibration settings,each set associated with a respective stored acoustic room response of aplurality of stored acoustic room responses; wherein the plurality ofsets of stored audio calibration settings are determined based onmultiple media playback systems each performing a respective audiocalibration process comprising (i) outputting, via a respective playbackdevice within a respective room that is different from the room in whichthe playback device is located, respective audio content, (ii) while therespective playback device outputs the respective audio content,capturing, via a microphone of a respective mobile device incommunication with the respective playback device, first respectiveaudio data representing reflections of the respective audio content inthe respective room while the respective mobile device is moving from afirst physical location to a second physical location within therespective room, and (iii) based on the first respective audio data,determining a set of audio calibration settings for the respectiveplayback device; wherein the plurality of stored acoustic room responsesare determined based on the multiple media playback systems eachperforming a respective acoustic room response determination processcomprising (i) while the respective playback device outputs therespective audio content, capturing, via a microphone disposed in ahousing of the respective playback device, second respective audio datarepresenting reflections of the respective audio content in therespective room, and (ii) based on the second respective audio data,determining an acoustic response of the respective room; querying thedatabase for a stored acoustic room response that corresponds to thedetermined acoustic response of the room in which the playback device islocated; responsive to the query, applying to the playback device aparticular set of stored audio calibration settings associated with thestored acoustic room response that corresponds to the determinedacoustic response of the room in which the playback device is located;and outputting, via the speaker of the playback device, second audiocontent using the particular set of audio calibration settingsassociated with the stored acoustic room response that corresponds tothe determined acoustic response of the room in which the playbackdevice is located.
 9. The tangible, non-transitory, computer-readablemedia of claim 8, wherein determining the set of audio calibrationsettings for the respective playback device comprises: based on thefirst respective audio data, determining audio characteristics of therespective room; and determining respective audio calibration settingsfor the respective playback device that offset the determined audiocharacteristics of the respective room.
 10. The tangible,non-transitory, computer-readable media of claim 8, wherein querying thedatabase comprises: mapping the acoustic response of the room in whichthe playback device is located to a particular stored acoustic roomresponse in the database that satisfies a threshold similarity to theacoustic response of the room in which the playback device is located.11. The tangible, non-transitory, computer-readable media of claim 8,wherein a self-response of the playback device is pre-determined in ananechoic chamber, and wherein determining the acoustic response of theroom in which the playback device is located comprises offsetting theself-response of the playback device from the captured audio datarepresenting reflections of the first audio content.
 12. The tangible,non-transitory, computer-readable media of claim 8, wherein aself-response of the microphone is pre-determined in an anechoicchamber, and wherein determining the acoustic response of the room inwhich the playback device is located comprises offsetting theself-response of the microphone from the captured audio datarepresenting reflections of the first audio content.
 13. The tangible,non-transitory, computer-readable media of claim 8, wherein outputting,via the speaker of the playback device, the first audio contentcomprises gradually increasing a volume level of the playback devicewhile outputting the first audio content, and wherein the operationsfurther comprise: while outputting the first audio content, measuring asignal-to-noise ratio of the first audio content to environmental noisein the room in which the playback device is located; and when thesignal-to-noise ratio exceeds a threshold value for calibration, ceasingto increase the volume level of the playback device and continuing tooutput the first audio content at the current volume level.
 14. Thetangible, non-transitory, computer-readable media of claim 8, whereinthe first audio content is different from the respective audio content.15. A method comprising: outputting, via a speaker of a playback device,first audio content; capturing, via a microphone of the playback device,audio data representing reflections of the first audio content within aroom in which the playback device is located; based on the capturedaudio data, determining an acoustic response of the room in which theplayback device is located; establishing a connection with a databasecomprising a plurality of sets of stored audio calibration settings,each set associated with a respective stored acoustic room response of aplurality of stored acoustic room responses; wherein the plurality ofsets of stored audio calibration settings are determined based onmultiple media playback systems each performing a respective audiocalibration process comprising (i) outputting, via a respective playbackdevice within a respective room that is different from the room in whichthe playback device is located, respective audio content, (ii) while therespective playback device outputs the respective audio content,capturing, via a microphone of a respective mobile device incommunication with the respective playback device, first respectiveaudio data representing reflections of the respective audio content inthe respective room while the respective mobile device is moving from afirst physical location to a second physical location within therespective room, and (iii) based on the first respective audio data,determining a set of audio calibration settings for the respectiveplayback device; wherein the plurality of stored acoustic room responsesare determined based on the multiple media playback systems eachperforming a respective acoustic room response determination processcomprising (i) while the respective playback device outputs therespective audio content, capturing, via a microphone disposed in ahousing of the respective playback device, second respective audio datarepresenting reflections of the respective audio content in therespective room, and (ii) based on the second respective audio data,determining an acoustic response of the respective room; querying thedatabase for a stored acoustic room response that corresponds to thedetermined acoustic response of the room in which the playback device islocated; responsive to the query, applying to the playback device aparticular set of stored audio calibration settings associated with thestored acoustic room response that corresponds to the determinedacoustic response of the room in which the playback device is located;and outputting, via the speaker of the playback device, second audiocontent using the particular set of audio calibration settingsassociated with the stored acoustic room response that corresponds tothe determined acoustic response of the room in which the playbackdevice is located.
 16. The method of claim 15, wherein determining theset of audio calibration settings for the respective playback devicecomprises: based on the first respective audio data, determining audiocharacteristics of the respective room; and determining respective audiocalibration settings for the respective playback device that offset thedetermined audio characteristics of the respective room.
 17. The methodof claim 15, wherein querying the database comprises: mapping theacoustic response of the room in which the playback device is located toa particular stored acoustic room response in the database thatsatisfies a threshold similarity to the acoustic response of the room inwhich the playback device is located.
 18. The method of claim 15,wherein a self-response of the playback device is pre-determined in ananechoic chamber, and wherein determining the acoustic response of theroom in which the playback device is located comprises offsetting theself-response of the playback device from the captured audio datarepresenting reflections of the first audio content.
 19. The method ofclaim 15, wherein a self-response of the microphone is pre-determined inan anechoic chamber, and wherein determining the acoustic response ofthe room in which the playback device is located comprises offsettingthe self-response of the microphone from the captured audio datarepresenting reflections of the first audio content.
 20. The method ofclaim 15, wherein outputting, via the speaker of the playback device,the first audio content comprises gradually increasing a volume level ofthe playback device while outputting the first audio content, andwherein the operations further comprise: while outputting the firstaudio content, measuring a signal-to-noise ratio of the first audiocontent to environmental noise in the room in which the playback deviceis located; and when the signal-to-noise ratio exceeds a threshold valuefor calibration, ceasing to increase the volume level of the playbackdevice and continuing to output the first audio content at the currentvolume level.